#pragma once
#include <iostream>
#include <string>
#include <vector>
#include <pthread.h>
#include <semaphore.h>
#include <unistd.h>
using namespace std;

template <class T>
class RingQueue
{
private:
    void P(sem_t &sem)
    {
        sem_wait(&sem);
    }
    void V(sem_t &sem)
    {
        sem_post(&sem);
    }
    void Lock(pthread_mutex_t &mutex)
    {
        pthread_mutex_lock(&mutex);
    }
    void UnLock(pthread_mutex_t &mutex)
    {
        pthread_mutex_unlock(&mutex);
    }
public:
    RingQueue(int cap):_cap(cap),_ring_queue(cap),_productor_step(0),_consumer_step(0)
    {
        sem_init(&_room_sem, 0, _cap);
        sem_init(&_data_sem, 0, 0);
        pthread_mutex_init(&_productor_mutex, nullptr);
        pthread_mutex_init(&_consumer_mutex, nullptr);
    }

    void Enqueue(T &in)
    {
        P(_room_sem);
        Lock(_productor_mutex);

        _ring_queue[_productor_step++] = in;
        _productor_step %= _cap;

        UnLock(_productor_mutex);
        V(_data_sem);
    }

    void Pop(T &out)
    {
        P(_data_sem);
        Lock(_consumer_mutex);

        out = _ring_queue[_consumer_step++];
        _consumer_step %= _cap;

        UnLock(_consumer_mutex);
        V(_room_sem);
    }

    ~RingQueue()
    {
        sem_destroy(&_room_sem);
        sem_destroy(&_data_sem);
        pthread_mutex_destroy(&_productor_mutex);
        pthread_mutex_destroy(&_consumer_mutex);
    }
private:
    vector<T> _ring_queue;
    int _cap;
    int _productor_step;
    int _consumer_step;
    sem_t _room_sem;
    sem_t _data_sem;
    pthread_mutex_t _productor_mutex;
    pthread_mutex_t _consumer_mutex;
};